Dim strSQL_Current as String
Dim strSQL_Temp As String
Dim qdf As DAO.Querydef
' replace queries SQL statement , substituting a date literal for the parameter
Set qdf = CurrentDb.querydefs("QueryNameGoesHere")
strSQL_Current = qdf.SQL
strSQL_Temp = Replace(trSQL_Current,"Forms!frmEmployees!txtDateAppointed", "#" & Format(Me.txtAppointed,"yyyy-mm-dd") & "#")
qdf.SQL = strSQL_Temp
' export query's result table to Excel
DoCmd.TransferSpreadsheet acExport, acSpreadsheetTypeExcel12Xml, "QueryNameGoesHere", strFilePath, True
' reinstate query's original SQL property
qdf.SQL = strSQL_Current